Sunday, May 20, 2007

Microwaves in Organic Synthesis

There are some good and recent reviews by Oliver Kappe (et al) on microwave-assisted organic synthesis:
1) "Microwave-Assisted Synthesis in Water as Solvent"; Chem Rev., 2007 (ASAP, DOI: 10.1021/cr0509410)

2) "The impact of microwave synthesis on drug discovery"; Nat Rev Drug Discov., 2006, 5(1), 51-63

3) "Controlled microwave heating in modern organic synthesis"; Angew Chem Int Ed Engl., 2004 , 43(46), 6250-84

I find them to be a useful guide to the microwave literature. The most recent review on water as a solvent is particularly interesting.

Tuesday, April 24, 2007

A bloody anticoagulant

I was pleasantly surprised to see the title of a manuscript in the journal Adv Exp Med Biol. The title reads "Antithrombin. A bloody important serpin."! Cool title. See here

T.V. Raghuraman's blog

My father is creating his own blog and is getting by with a little help from my brother! You should be able to find some fascinating anecdotes on T.V.R's blog (see "Links")

Thursday, October 12, 2006

Prasanna's New Album

For those who like "fusion" music, Prasanna's "Electric Ganesha Land" is a must-have. I am listening to "Dark Sundae in Triplicane" as I type this and am just amazed by the composition.

Friday, October 06, 2006

Specificity in the Interaction of Glycosaminoglycan Sequences

Its amazing how one problem leads to another in research. I was asked by my advisor to design modular mimics of heparan sulfate (HS), a glycosaminoglycan that is involved in binding several different proteins in our body. The end goal was to be able to mimic a given sequence of a HS molecule with a non-sugar molecule resulting in a cost-effective and easily synthesizable therapeutic agent. In trying to achieve this goal, I came across a more fundamental problem.

The “Glycosaminoglycan Problem”

HS, in principle, is made of 48 different disaccharides although only 23 have been identified to date. Even with 23 disaccharides, 23 х 23 х 23 = 12,167 different hexasacharide structures are possible, which is highly significant in the biological realm of ligand-mediated modulation of protein function. Variability in these 12,167 molecules results from different sulfate group arrangements, different uronic acid structures, different uronic acid conformers, and different glycosidic bond torsions. What is not known is 1) how many of these structures are important in vivo?, 2) How diverse are they really, i.e. do small changes in structure (e.g. deletion of a single sulfate group) cause significant differences in protein binding?
From a medicinal chemistry perspective, it would be a great challenge to target a given glycosaminoglycan-binding protein by engineering a specific HS sequence. Such a sequence need not be physiologically relevant but would certainly be therapeutically valuable. Thus, in an effort to design modular mimics of HS, I found myself digging deep into the glycosaminoglycan literature trying to understand and define the concept of glycosaminoglycan-sequence specificity!

Thursday, December 29, 2005

Welcome to my blog

Hello, I am Arjun Raghuraman, a graduate student of Medicinal Chemistry at Virginia Commonwealth University, Richmond, USA. As an undergraduate, I spent four years studying Pharmaceutical Science at S.R.M. College of Pharmacy, Chennai, India. These four years established my foundations in Organic and Physical Chemistry, and piqued my interest in Medicinal Chemistry, a fascinating science that uses the prinicples of Chemistry and Biology to create new molecules that could ultimately be developed into new medicines.

Currently, I am studying a diverse class of molecules called glycosaminoglycans (GAGs) under the tutelage of Dr. Umesh Desai. The aim of my project is to study the interaction of GAGs with proteins and use this information to design and synthesize various mimics of GAGs that could serve as anti-coagulants, anti-viral agents, and possibly anti-cancer agents.

Over the next few years, I will post new information about my research with links to my publications. I will also post short accounts of my understanding of scientific topics that interest me.